Improvement in stone-dressing machines



UNTTED STATES PATENT OFFICE.

WILLIAM EAYRS, OF CONCORD, NET HAMPSHIRE.

IMPROVEMENT IN STONE-DRE'SSING MACHINES.

Specification forming part of' Letters Patent No. 6,919, dated December4, 1849.

To .aZZ wir/0172, t may concern;

Be it known that l, WILLIAM EAYEs, of Concord, in the county of Merrimacand State of New Hampshire, have invented a new and useful or ImprovedMachine for Cutting or Dressing Stone; and I do hereby declare that thesame is fully described and represented in the following specificationand accompanying drawings, letters, figures, and references thereof. g

In the said drawings, Figure l denotes a top view of my improvedmachine. Fig. 2 is a front end elevation of it. Fig. 3 is a verticallongitudinal and central section of it. Fig. 4 is a side elevation ofit. f

Many attempts to produce a practical operating stone cutting or dressingmachine have been made, and several machines in their construction andoperation have nearly approached my machine. There is, however, adierence or dierences between them and mine, which though apparentlysmall will be found to be of great importance, inasmuch as thesedierences, I apprehend, render my machine of as much if not a fargreater value in its results when compared with them as is the Woodworthplaning-machine in comparison with various other kinds ofplaning-machines constructed and used previous to the date of itsinvention. I believe, from the amount of stone my machine is capable ofdressing in any time, that there is no other machine in existence whichproduces the same extent of work in the same time and with so littleexpense. In its construction I have aimed at simplicity combined withgreat practical effects, and from the evidences produced by theoperation of it I have good reason to think I have entirely succeeded inattaining the desired end. These remarks I make as a master workman longskilled in the art of hammering stone, one who by many years of practicehas become acquainted with most if not nearly all the difficulties to beovercome. I make them with no visionary or egotistical spirit, butsimply in order that my invention may be duly and properly consideredboth at the Patent Office and elsewhere.

The whole of my invention is to be found not only in the manner in whichor by which I sustain and operate each of the chisels, but also in themeans adopted ,to produce the percussion or blow thereon necessary tocause it to remove the surplus material from the block of stone. I wouldfurther remark that while a stone-cutter with his chisel and mallet orhammer is in the act ofy cutting a stonehe places and holds his chiselagainst the part to be separated, and while so held against the same hegives the blow upon the head of the chisel. In order to produce goodwork he must always, at the time of giving the blow,

hold the cutting-edge of the chisel firmly y or close against the partto be chipped off. Otherwise the rebound of the chisel will take place,whereas it is desirable that the chisel should follow up the blow andthe rebound be in the hammer alone, if anywhere.

From the above remarks and the following description it will be seenthat my machine cuts the stone in very much the same manner in which aworkman would with a chisel and mallet, and at the same time does thesame with much greater rapidity.

In Figs. 2 and 3 of the above-mentioned drawings, a d c2 d3, dsc., are aseries of chisels affixed, respectively, in and made to project from thelower ends of a series of chisel-holders b b b2 b3, ttc., each of saidchisels being held in place in its holder by any suitable means. Each ofsaid holders has alongitudinal shape, as seen in section in Fig. S-thatis to say, it is composed of two parts making an angle to each other.-The upper or longest part rests at its lower end on a stationarycross-bar or rest-bar c, while at. its upper end it turns freely in avertical plane on ahori` zontal rod (l, which, together with the restbarc, extends between and is firmly fastened to the sectional sides e f ofa frame A. The said two sides e f have arcsof cogs g g,and each issupported at or near its lower end by a journal made to projectlaterally from it, as seen by dotted lines at h t'. These journals restand turn in suitable bearings made in or affixed to a mainsupporting-frame B.

The frame A supports a horizontal and transverse shaft 7c, on which therotary hammers ZZ Z2 Z3, &c., are affixed, and by which they are made torevolve whenever the said shaft is put in rotation on its axis. Each ofthe said rotary hammers consists of a heavy block or piece of metalaffixed to the shaft and made with one or more striking-faces m standingfrom it, as seen in Fig. 3. From the upper or outer edge of the saidstriking-face the hammer 'or' block isl 'gradually curved down,l asvseen'at-n, to thefootof the succeeding striking-face, in case there ismore. than one face to each block; but where each rotary block has butone striking-face the curve extends from the outer edge of the faceentirely around the block and to the lower edge of the face. The objectof this curve is to permit the chisel-holder to be moved away from therest-bar after each stroke of a hammer-face, the s'aid niovementbeingproduced in consequence of the progressive forward movement of thestone, as will be hereinafter explained.

On one end of the shaft k of the rotar-y hammer a gear-wheel o is iixed.This gear engages with another gear-wheel p, which is placed and movesloosely on the journal h. A drum or. pulley q is attached to the side ofthe gear p and made to be moved or rotated by an endless belt r, whichalso passes around a drum or pulley s, fixed on one end of thehorizontal driving-shaft t. The said drivingshaft t runs in proper boxesa o, and has a fast pulley fw and a loose pulley @c affixed to it, andfor the purpose of receiving an endless belt from any suitabledriving-power.

A horizontal crank-shaft D is disposed transversely over the frame A,and has two pinions E E fixed on it, the said pinions being,respectively, made to engage with the toothed gears of the frame A. Byapplying the hand to the crank G of the said shaft andl rotating 4it theinclined or angular position of the chisels may be varied at pleasure.Vhen they are arranged in any assumed angular position with respect tothe upper surface of the stone, such position may be maintained byslipping a movable lever or catch H into one of the indentations of anotched wheel I, fixed-on the shaft D.

The stone to be dressed or cut is placed on a platform K, which shouldbe disposed below the chisels and have suitable machinery applied to itfor the purpose of imparting to it a proper progressive forward movementunder the cutters. To this portion of the machinery, (separate from therest,) as well as any contrivance for giving motion to it, I lay noclaim, as the same may be said to be in use in other stone-dressingmachines.

In the drawings I have exhibited another set of hammers, chisels, andtheir operating -progressively toward the chisels.

machinery, the same being seen at L, and so placedwith respect to thathereinbefore described as t o operate on the stone after it has beensubjected to the action of the first. This second set of machinery,which differs in no material respect from the first, except in the widthof the cutting-chisels, is but a repetition of the first and onlyintended to dress or finish the surface of the stone after it has beencut by the first set of chisels. While the stone is in the act of beingcut its portion to be removed should be moved regularly and Previous,however, to each blow of a hammer-face on a chisel the projecting partof the stone 'against which the edge of the chisel is to be driven hasbeen so moved against the chisel-edge as to press it forward on itsholder in a direction off or 'away from the rest-bar. This takes placepreparatory to each blow of the hammer, which immediately followingforces the chisel into the stone until the chiselholder again meets andrests upon the rest-bar.

From this it will be seen that when the blow of the hammer takes placethe chisel is held closely against that part of the stone to be chippedoff in essentially the same way as a workm an with one hand usuallyholds a chisel against the stone preparatory to giving it a blow with ahammer held in his other hand. I make use of no spring or othercontrivance to elevate the chisel and its stock or holder; but I causeit by the mere movement of the stone against it to be prepared for eachblow of its rotary hammer.

I wish it distinctly understood that I lay no claim to the invention ofone or more chisels and one or more hammers as arranged, constructed,and applied to cutting or reducing stoneprevious to the date of myiuvention or improvements; but

vThat which I do claim is as follows, viz:

The rotary hammer as constructed and com` bined with each chisel-stockand made to iin-y pinge against it and permit it to immediatelyafterward move'forward preparatory to anl other blow, essentially asspecified.

In testimony whereof I have hereto set my signature this Sth day ofAugust, A. D; 1849.

e 'XVILLIAM EAYRS.

Y I'Vitnesses:

STEPHEN C. BADGER, R. G. CUTTING.

